1. Field of the Invention
The present invention relates generally to an improved approach for automatic detection and synchronization in handheld electronic units such as cell phones, etc. that may have the need for add-on units to be connected thereto. Such devices may include barcode scanners, PDAs, printers, scanners, and the like.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Hand held units such as computers, cell phones, personal digital assistants (PDAs) etc are becoming increasingly useful amongst consumers and industry. The connection of such devices to each other via various communication protocols would be most desirable if one device were to be able to detect the connection of other devices automatically and performs predefined data exchange process, especially if there were a straight forward method for auto detection and auto data exchange process, unfortunately this kind of auto device detection and auto data exchange method is not available in the prior art, such that serial and/or Bluetooth protocol or devices simply cannot provide for auto serial device detection and data exchange.
Prior art attempts, such as those exemplified by documents such as U.S. Pat. Nos. 5,649,210, 5,812,796, 5,721,458, 5,991,885, and 6,772,249, each of which are hereby incorporated by reference in their entireties, offer only crude solutions for attempting to determine if there is another device connected on the interface and sending data. Such prior art attempts typically revolve around either the manual launching of a communication routine through an interface means, or through the sending of an interrupt to the main processor when the UART receive-buffer receives data, and the constant polling of the UART status to see if there is data in the buffer. Such approaches, especially those involving polling techniques, have several flaws, the most significant of which is that the usage of constant polling is primarily directed at systems with embedded processors that do not have an available interrupt for UART buffer status, and in all cases, creates a resource drain on processor execution time, as well as a power drain on the batteries of portable devices.
Related attempts have been hitherto limited to the provision of say, polling or the like, but provision of such means that such devices would not have the capability for providing a signal that can offer connection detection. Because there are no additional signal lines available in the RS-232 standard used in prior art systems, there simply is no signaling means to show that one given device is connected to another device on its interface, and as such, auto detection is not possible. Even if one were somehow to try to utilize a USB-like auto detection (like that found in a PC), it simply would not be possible retrofit the existing serial connection wiring to accommodate the USB-like auto detection, and as such, this type of solution cannot be readily utilized when plugging into a device other than a PC. Moreover, the above approaches are particularly resource and power intensive, and in any case, still do not provide for the desired auto detection. Given the various drawbacks related to the usage of “polling” in serial connections, and considering the inability of serial devices to accommodate USB-like auto detection, there is clearly a need to provide for auto detection that works within the limitations of serial connectivity without the aforementioned drawbacks.